Micro Screwdriver Types

[wiseman]

I was wondering, what is the difference between a Phillips tip screwdriver and a JIS cross point screwdriver? Are the JIS types the correct tool to use on the small lens screws?

I’m going to try and repair my SMC F 70-210 lens. The focus mechanism gets jammed frequently. Otherwise it is a terrific lens!

p.s. I have read that some screws use thread locking compound. What is the best way to defeat the thread lock compound? I have read of using nail polish or heat (soldering iron). I would think either of those methods could damage plastic threads.

Thanks in advance for all your help

[Lowell Goudge]

I have found that many screws are either put in with thread locking or effectively glued down with a small dab of paint or adhesive.

I have also found that many precision screw-drivers are made with brass tips or soft steel not hardened steel.

The best ones I have found are the cheap kits with chrome bodies and black shafts (usually hard but brittle) they last for a little while then shatter.

You might try snap on tools to see if they make a better quality one.

Also you might need a special tool to remove the large diameter rings, usially they have a notch on both sides for a tool, but I don't know what that is called

[wiseman]

Thank you Lowell for your insight. I will be ordering a spanner wrench to remove the lens rings. How have you gotten around the thread lock compound?

[BobG]

I recommend this company for good quality precision tools.

https://www.micro-tools.com/

BobG